2016

2016

Environmental Toxicology Program

Bureau of Environmental Health

Massachusetts Department of Public Health

250 Washington Street

Boston, MA 02108

Email: dph-beach@state.ma.us

Phone: (617) 624-5757

Massachusetts Beach Testing Results: Annual Report

Good Harbor Beach, Gloucester, MA

1

2016

Executive Summary

Swimming at Massachusetts beaches is one of the most popular recreational activities in the state, with over

111 million individual trips to one of the 1,100 beaches each year (EOEEA, 2007; EOHED, 2016). As good water

quality is essential to having a safe and enjoyable beach visit, it is critical to both monitor the water quality and

immediately notify the public of any potential water quality concerns. Each year, the Environmental Toxicology

Program in the Massachusetts Department of Public Health (MDPH), Bureau of Environmental Health collects

water quality information from local health departments as well as the Massachusetts Department of

Conservation and Recreation. This report provides a description of this information and is summarized

immediately below.

Water quality: In 2016, a total of 15,604 water samples were collected from 586 marine and 594

freshwater beach sampling locations. These locations represent 529 marine and 549 freshwater

beaches. All marine beach communities and 99% of freshwater communities reported water quality

information to MDPH. Approximately 3.5% and 3.0% of the samples exceeded the Massachusetts water

quality standards (based on bacteria) for marine and freshwater beaches, respectively. The overall low

exceedance rates indicate that Massachusetts beaches have generally high water quality. Elevated

bacteria accounted for 63% of poor water quality notifications (i.e., beach postings); other reasons for

notifications included harmful algae (cyanobacteria) blooms, rainfall (typically associated with elevated

bacteria), and other hazards (e.g., strong currents, shark sightings).

Field data: In 2016, a majority of water samples (approximately 93%) submitted to MDPH had

accompanying field data. Rainfall and local pollution sources at sampling sites were identified as two

important factors that contributed to elevated bacteria levels at recreational waterbodies. Generally,

the number of exceedances dropped exponentially as the days since rainfall increased. Among those

samples collected near potential pollution sources, the exceedance rate was higher than those without a

potential pollution source.

Public notification: The MDPH marine beaches website (http://ma.healthinspections.us/public_21/)

provides near real-time information on bacteria levels at public marine beaches, as well as information

on historic bacteria levels. MDPH initiated usage analyses of its beaches website in 2016 by recording

the number of unique visitors. The number of website users was highest in July and August, which

corresponded with the height of the beach season in Massachusetts. Individuals were also notified of

unsafe conditions at beaches through the use of physical signage that is required to be posted by beach

operators. All marine and 74% of freshwater beaches were in compliance with the public notification

requirement. The 100% marine compliance is a first since the passage of the Massachusetts Beach Act.

2

2016

Introduction

Swimming-associated health risks have been documented

in numerous studies (Marion et al., 2010; Wade et al.,

2003). Beachgoers may be exposed to pathogens through

recreational activities in and around polluted waterbodies

(Hlavsa et al., 2015). In the United States, most

swimming-associated diseases are caused by a variety of

pathogens associated with fecal contamination (Cabelli et

al., 1982; USEPA, 2012). Human fecal matter can enter

beach water in a variety of ways, including sewage

treatment system failures, combined sewer overflows,

discharge of sewage by boats, re-suspension of

sediments, and rainfall and resulting surface runoff (Galfi

et al., 2016; Rodrigues et al., 2016).

To address concerns over swimming-associated illness,

improve public health for beachgoers, and notify the

public about the quality of beach water, MDPH

regulations have required regular water quality

monitoring and public notification of unsafe conditions

since 2001. All public and semi-public bathing beaches in

Massachusetts are monitored for fecal indicator bacteria

(FIB), and on occasion harmful algae during the beach

season which generally begins when the school year

finishes in mid-June and ends during the weekend of

Labor Day.

MDPH adopted the USEPA criteria for enterococci and

E. coli in marine and freshwater. These criteria consist of

both a single sample and geometric mean (geomean)

value reported as colony forming units per 100 milliliter

of water (CFU/100mL) (see Table). When beach water

does not meet these water quality standards, MDPH

requires that the beach be posted with a notice alerting

the public to the possible risk of swimming. At a majority

of beaches in Massachusetts, water quality is considered

to be unacceptable when two samples collected on

consecutive days exceed the water quality standards.

Beaches with a history of multi-day elevated bacteria

levels are required to post after a single exceedance.

Posting is also required when the geomean of the five

most recent non-rainfall impacted samples exceeds the

geomean standard.

Table. MDPH recreational water quality criteria (CFU/100 mL)

In addition to water samples, field data such as days since

rainfall and potential pollution sources are required to be

collected at the time of sample collection. Field data help

facilitate the interpretation of bacteria data and can

improve the understanding of water quality at the local

and state level.

Spring Brook Park Beach, Bedford, MA

Beach

Type Indicator

Single

Sample Geomean

Marine Enterococci >104 >35

Freshwater Enterococci >61 >33

E. coli >235 >126

3

2016

Water Quality

Marine beach exceedances. During the 2016 beach

season, a total of 7,904 samples were collected and

analyzed from 586 marine beaches. Of these 586

beaches, 140 (24%) in the 60 communities with beaches

had at least one bacterial exceedance (see Figure 1). A

total of 274 out of the 7,904 samples exceeded the 104

CFU/100 mL standard. The percentage of exceedances for

marine waters in 2016 was 3.5%, which was much lower

than the historical average exceedance rate of 4.9%. The

number of marine beach exceedances in each community

during 2016 is shown in Figure 1. The marine beaches in

Boston, Lynn, and Quincy had the highest number of

exceedances in 2016.

Freshwater beach exceedances. During the 2016 beach

season, 7,700 samples from 594 freshwater beaches

were collected and analyzed for the approved FIB (i.e. E.

coli or enterococci). Most freshwater beaches (87%) used

E. coli. Among the 594 freshwater beaches, 115 (19%) in

180 communities reporting beach data had at least one

bacterial exceedance (Figure 2). A total of 232 out of the

7,904 samples exceeded the standard. The percentage of

exceedances for freshwater in 2016 was 3.0%, which was

much lower than the historical average exceedance rate

of 3.8%. The number of freshwater beach exceedances in

each community during 2016 is shown in Figure 2. The

number of exceedances in freshwater beaches in 2016

varied among communities, with the highest number in

Brimfield, Templeton, and West Tisbury.

Posting beaches. During the 2016 beach season, poor

water quality and/or unsafe conditions required the

postings of beaches on 274 occasions. These postings

advised individuals not to swim or bathe in the water.

Figure 3 displays the causes of postings in 2016. The

majority of postings were due to the exceedance or

expected exceedance (i.e., rainfall) of water quality

standards. For marine beaches, there were 160 postings

due to elevated bacteria, rainfall, or other (e.g., rip

current, shark sightings). For freshwater beaches, there

were 114 postings due to elevated bacteria, rainfall, and

harmful algae blooms.

Figure 3. Posting details for marine and freshwater beaches in 2016

Figure 1. Marine beach water quality exceedances in 2016

Figure 2. Freshwater beach water quality exceedances in 2016

4

2016

Field Data Potential pollution sources. The presence of pollution

sources at beaches was associated with a higher risk of

bacterial exceedances. Figure 4 shows that the

exceedance rate of samples which noted the presence of

specific pollution sources is higher than those without the

presence of any pollution source regardless of beach

type. It is worth mentioning that when pollution source

information was not reported (i.e., unknown) in the field

data, the exceedance rate of water samples was even

higher than those with the presence of a specific

pollution source. Without pollution source information,

the ability to evaluate the potential impacts on water

quality is diminished.

Figure 4. Exceedance rate of water samples associated with the presence, absence, or none reporting of environmental pollution sources at beaches in Massachusetts in 2016

Unknown: no information provided; yes: specific pollution source observed; no: no pollution source observed.

Rainfall. Rainfall is recognized as one of the major drivers

of bacterial exceedances in beach water (Harder-

Lauridsen et al., 2013). An exponential drop in the

number of exceedances occurs as the time between

rainfall and sample collection increases (Figure 5). For

marine beaches, 158 of 274 bacterial exceedances

occurred within 24 hours after a rain event; for

freshwater, 126 of 230 exceedances were observed

within 48 hours after a rain event.

Figure 5. Relationship between the number of bacterial exceedances and days since rainfall in 2016

The historical relationship between exceedances of water

quality criteria at marine and freshwater beaches and the

total amount of rainfall between June and August is

shown in Figure 6. The rainfall data were obtained from

the National Oceanic and Atmospheric Administration

(NOAA, 2016). Rainfall data sets from Boston and

Chatham were used to represent monthly rainfall

amounts at marine beaches; data sets from Amherst and

Ashburnham, along with those from Boston and Chatham

were used to represent amounts at freshwater beaches.

For both marine and freshwater beaches, exceedances

generally rise and fall with rainfall amounts, with some

exceptions. In 2016, Massachusetts received the least

amount of rain during any beach season since 2001. The

low rainfall amount is likely a primary reason for the low

exceedance rates in 2016.

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2016

Figure 6. The historical relationship between rainfall amounts and exceedance rates at (A) marine and (B) freshwater beaches in Massachusetts from the 2001 to 2016 beach seasons

Public Notification

Beach website. The MDPH beach monitoring website

(http://ma.healthinspections.us/public_21/) provides the

public with the most up-to-date marine beach testing and

posting information and presents the data in an easy-to-

use format. Overall, over 4,000 users visited the website

during the season (this includes both new and returning

users). An analysis of weekly usage data demonstrated

an increase in the number of users as the beach season

progressed and consistent usage during the second half

of the season (Figure 6). The number of website users

(n=398) peaked during week 9, which corresponds with

late July. The second busiest week was that which

included July 4th (week 6), when 364 people visited the

site.

Beach postings. When water quality standards are

exceeded or other safety concerns warrant, beach

operators are required to post signage at the beach

advising individuals of the hazard and recommending

they stay out of the water. This is an essential part of the

public notification system. Marine and freshwater

beaches were posted properly 100% and 75% of the time,

respectively.

Figure 7. Number of MDPH marine beach website users per week during the 2016 beach season

Conclusions

In 2016, the exceedance rates at marine and freshwater

beaches were lower than historical averages. Rainfall is a

significant driver of bacteria exceedances, and the low

rainfall amount received throughout the beach season

across the state is likely a primary factor for the low

exceedance rates. However, given the number of beaches

sampled in Massachusetts, the average historical

exceedance rates of less than 5% indicate that

Massachusetts has beaches with generally high water

quality. Public notification of marine results and postings

via MDPH’s monitoring website continued to be an

effective means of communicating with the public.

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2016

Acknowledgements

This work was partially supported by a U.S. EPA Beaches Environmental Assessment and Coastal Health (BEACH) grant and a U.S. Centers for Disease Control and Prevention’s Preventive Health and Health Services grant. MDPH received assistance from local, regional, and state partners, including Massachusetts boards of health, regional health networks, and the Massachusetts Department of Conservation and Recreation, in ensuring that bathing beaches were tested and data were submitted appropriately.

References

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Swimming-associated gastroenteritis and water quality.

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Executive Office of Energy and Environmental Affairs

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Executive Office of Housing and Economic Development

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content/uploads/2016/09/2015-annual-report-9-27-

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Galfi, H., Österlund, H., Marsalek, J., Viklander, M. 2016.

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urban catchments. Journal of Hydrology 539, 125-140.

Harder-Lauridsen, N.M., Kuhn, K.G., Erichsen, A.C.,

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Beach, M., Wade, T., Yoder, J. 2015. Outbreaks of Illness

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Marion, J.W., Lee, J., Lemeshow, S., Buckley, T.J. 2010.

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water exposure at an inland U.S. beach. Water Research

44, 4796-4804.

Rodrigues, V.F.V., Rivera, I.N.G., Lim, K.-Y., Jiang, S.C.

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coli in recreational beaches of Brazil. Marine Pollution

Bulletin 109, 163-170.

U.S. Environmental Protection Agency (US EPA), 2012.

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12-058, Office of Water.

Wade, T.J., Pai, N., Eisenberg, J.N., Colford, J.M.J. 2003.

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5

2016

For more information, please visit:

MDPH Beaches and Algae website: http://www.mass.gov/dph/beaches

MDPH Marine Beach website: http://ma.healthinspections.us/public_21/

Or contact:

Environmental Toxicology Program

Bureau of Environmental Health

Massachusetts Department of Public Health

250 Washington Street

Boston, MA 02108

Email: dph-beach@state.ma.us

Phone: (617) 624-5757

Fax: (617) 624-5813

South Beach, Edgartown, MA